public class User {
    private String account;
    private String password;
    private String email;

    public User(String account, String password, String email) {
        this.account = account;
        this.password = password;
        this.email = email;
    }
    public User(String account, String password) {
        this(account, password, "");
    }
    public void showInformation() {
        System.out.println("账号：" + account + " 密码：" + password + " 邮箱：" + email);
    }

    public static void main(String[] args) {
        User user1 = new User("123", "abc", "123abc@qq.com");
        User user2 = new User("456", "def");
        user1.showInformation();
        user2.showInformation();
    }
}
